18.21.5 Macros for DWARF Output

Here are macros for DWARF output.

Macro: DWARF2_DEBUGGING_INFO

Define this macro if GCC should produce dwarf version 2 format debugging output in response to the -g option.

Target Hook: int TARGET_DWARF_CALLING_CONVENTION (const_tree function)

Define this to enable the dwarf attribute DW_AT_calling_convention to be emitted for each function. Instead of an integer return the enum value for the DW_CC_ tag.

To support optional call frame debugging information, you must also define INCOMING_RETURN_ADDR_RTX and either set RTX_FRAME_RELATED_P on the prologue insns if you use RTL for the prologue, or call dwarf2out_def_cfa and dwarf2out_reg_save as appropriate from TARGET_ASM_FUNCTION_PROLOGUE if you don’t.

Macro: DWARF2_FRAME_INFO

Define this macro to a nonzero value if GCC should always output Dwarf 2 frame information. If TARGET_EXCEPT_UNWIND_INFO (see Exception Region Output) returns UI_DWARF2, and exceptions are enabled, GCC will output this information not matter how you define DWARF2_FRAME_INFO.

Target Hook: enum unwind_info_type TARGET_DEBUG_UNWIND_INFO (void)

This hook defines the mechanism that will be used for describing frame unwind information to the debugger. Normally the hook will return UI_DWARF2 if DWARF 2 debug information is enabled, and return UI_NONE otherwise.

A target may return UI_DWARF2 even when DWARF 2 debug information is disabled in order to always output DWARF 2 frame information.

A target may return UI_TARGET if it has ABI specified unwind tables. This will suppress generation of the normal debug frame unwind information.

Macro: DWARF2_ASM_LINE_DEBUG_INFO

Define this macro to be a nonzero value if the assembler can generate Dwarf 2 line debug info sections. This will result in much more compact line number tables, and hence is desirable if it works.

Macro: DWARF2_ASM_VIEW_DEBUG_INFO

Define this macro to be a nonzero value if the assembler supports view assignment and verification in .loc. If it does not, but the user enables location views, the compiler may have to fallback to internal line number tables.

Target Hook: int TARGET_RESET_LOCATION_VIEW (rtx_insn *)

This hook, if defined, enables -ginternal-reset-location-views, and uses its result to override cases in which the estimated min insn length might be nonzero even when a PC advance (i.e., a view reset) cannot be taken for granted.

If the hook is defined, it must return a positive value to indicate the insn definitely advances the PC, and so the view number can be safely assumed to be reset; a negative value to mean the insn definitely does not advance the PC, and os the view number must not be reset; or zero to decide based on the estimated insn length.

If insn length is to be regarded as reliable, set the hook to hook_int_rtx_insn_0.

Target Hook: bool TARGET_WANT_DEBUG_PUB_SECTIONS

True if the .debug_pubtypes and .debug_pubnames sections should be emitted. These sections are not used on most platforms, and in particular GDB does not use them.

Target Hook: bool TARGET_DELAY_SCHED2

True if sched2 is not to be run at its normal place. This usually means it will be run as part of machine-specific reorg.

Target Hook: bool TARGET_DELAY_VARTRACK

True if vartrack is not to be run at its normal place. This usually means it will be run as part of machine-specific reorg.

Target Hook: bool TARGET_NO_REGISTER_ALLOCATION

True if register allocation and the passes following it should not be run. Usually true only for virtual assembler targets.

Macro: ASM_OUTPUT_DWARF_DELTA (stream, size, label1, label2)

A C statement to issue assembly directives that create a difference lab1 minus lab2, using an integer of the given size.

Macro: ASM_OUTPUT_DWARF_VMS_DELTA (stream, size, label1, label2)

A C statement to issue assembly directives that create a difference between the two given labels in system defined units, e.g. instruction slots on IA64 VMS, using an integer of the given size.

Macro: ASM_OUTPUT_DWARF_OFFSET (stream, size, label, offset, section)

A C statement to issue assembly directives that create a section-relative reference to the given label plus offset, using an integer of the given size. The label is known to be defined in the given section.

Macro: ASM_OUTPUT_DWARF_PCREL (stream, size, label)

A C statement to issue assembly directives that create a self-relative reference to the given label, using an integer of the given size.

Macro: ASM_OUTPUT_DWARF_DATAREL (stream, size, label)

A C statement to issue assembly directives that create a reference to the given label relative to the dbase, using an integer of the given size.

Macro: ASM_OUTPUT_DWARF_TABLE_REF (label)

A C statement to issue assembly directives that create a reference to the DWARF table identifier label from the current section. This is used on some systems to avoid garbage collecting a DWARF table which is referenced by a function.

Target Hook: void TARGET_ASM_OUTPUT_DWARF_DTPREL (FILE *file, int size, rtx x)

If defined, this target hook is a function which outputs a DTP-relative reference to the given TLS symbol of the specified size.